TPS2373: TPS2373-4 for 60W application

Hironori Yoshimura

Part Number: TPS2373
Other Parts Discussed in Thread: TEST

I understand that inside FET(2373-4=0.1ohms, 2373-3: 0.3ohms) is different value.
my customer has already registration (CPN) by TPS2373-4 device for 70W PoE.

Do you have any risks if my customer apply TPS2373-4 for 60W PoE application?

4 months ago

0 Michael Pahl 4 months ago

TI__Mastermind 21105 points

Hello,

The -3 and -4 relates to the PoE Type Power levels -- Type 3 = 51W, and Type 4 = 71W.

A 60W application should use the -4 part because it exceeds the 51W limit.

So yes it should be good.

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Hironori Yoshimura 4 months ago in reply to Michael Pahl

TI__Intellectual 1230 points

Micheal, Sorry for confusion. Just in case if customer use TPS2373-4 for 51W application, What kind of risks are expected ?

I assume in-rush current is larger when use TPS2373-4 against 51W apps with TPS2373-3.
If you have another risks, please let me know?

+1 Michael Pahl 4 months ago in reply to Hironori Yoshimura

TI__Mastermind 21105 points

Hello,

If they use the TPS2373-4 there is no risk for 51W application. The -4 internal hotswap FET can withstand up to 71W, so it can be used for any power level less. They are just paying a price premium for a -4 FET vs. the TPS2373-3 FET.

The in-rush current is actually well defined by the IEEE802.3.bt standard, so in order to be compliant it has to be within a certain limit. So the in-rush should not effect the design.

So there should be no risks. The TPS2373-4EVM-758 actually has jumpers for the classification resistors, so you or customer can order an EVM and set it to Class 6 (51W) and test with a PSE. This will show how there is no risk of -4 part operating at 51W.